North Dakota Democratic Rep. Earl Pomeroy will not run for the Senate in 2010.

(CNN) – North Dakota Rep. Earl Pomeroy will not run for the Senate in 2010, two Democratic congressional leadership sources tell CNN.

Pomeroy will make the announcement this afternoon that he will not seek to succeed retiring Sen. Byron Dorgan, a fellow Democrat. A Senate Democratic leadership source noted that national Democrats are eyeing former state Attorney General Heidi Heitkamp as a possible candidate to run for the seat.

MSNBC talk show host Ed Schultz said in an interview on the cable network Wednesday that a state Democratic leader has reached out asking him to consider running for Dorgan's seat.

(CNN) - Sen. Joe Lieberman, Chris Dodd's fellow Connecticut senator, issued a statement hailing Dodd's retirement as the end of a "remarkable era of service in the Senate."

Full statement:

“Chris Dodd has been a genuinely great Senator for our state and country, and a close and valued friend and colleague for me. His retirement ends a remarkable era of service in the Senate by two generations of the Dodd family, beginning with his father Tom who was elected more than a half century ago in 1958.

“Chris Dodd has been an unusually skillful and productive legislator and leaves a great legacy of accomplishment that has improved the lives of millions of American families and children. I am sad for our state and country, and for myself frankly, that Chris is leaving the Senate but I am happy for his family that he will have more time to spend with them now. And I know that his service to America and our friendship will continue in different ways in the years ahead.

“Senator Chris Dodd will leave the Senate in January 2011 with the knowledge that he has made a difference that will last in the lives of his constituents and his country. For that, we are all grateful.”

He had been winning congressional elections in his state since 1974, but he's recently been considered one of the most vulnerable Democrats seeking re-election in 2010. Dodd has been trailing likely Republican challengers in recent polls, even though Connecticut typically leans Democratic.

National Republicans are wasting little time in building an opposition research file against Connecticut Attorney General Richard Blumenthal.

(CNN) – National Republicans wasted little time Wednesday in building an opposition research file against Connecticut Attorney General Richard Blumenthal, who will announce later in the day he will run for the Senate this year, CNN has learned.

The National Republican Senatorial Committee sent a request this morning to Blumenthal's office asking for copies of information ranging from "budget requests" and "state credit cards issued to Attorney General Blumenthal or provided for his use" to statistics on "plea bargain rates, felony conviction rates, and all other data associated with cases handled by the Office of the Attorney General for each year beginning in 1991 through present."

Blumenthal, a Democrat first elected as attorney general in 1990, will run for retiring Democratic Sen. Chris Dodd's seat. Former Rep. Rob Simmons and businesswoman Linda McMahon are seeking the GOP Senate nomination.

The NRSC asked for the information about Blumenthal under the state's Freedom of Information Act.

Colorado Gov. Bill Ritter has decided not to run for re-election this November, a Democratic Party source tells CNN.

Washington (CNN) - Colorado Gov. Bill Ritter has decided not to run for re-election this November, a Democratic Party source tells CNN.

Ritter, a Democrat who comfortably won a first term in 2006, was facing a tough re-election battle against former Republican Rep. Scott McInnis.

Both the Cook Political Report and the Rothenberg Political Report, two well respected non-partisan analysts, considered the race a toss up. There are 37 governorships are up for grabs in 2010, with Democrats defending 19 seats and the GOP 18 seats.

Colorado will become the 11th open seat the Democrats have to defend. The Republicans are also defending 11 open seats.

(CNN) - Wisconsin Rep. Paul Ryan, widely viewed as a rising star in the Republican Party and a favorite among conservatives, is endorsing former Florida House Speaker Marco Rubio's bid for the Senate Republican nomination in that state.

"In the coming years, America faces critical decisions on government spending, taxes and entitlements that will require idea-driven leaders," Ryan said in a statement released by the Rubio campaign. "Marco Rubio has proven he is exactly the type of consistent, principled conservative the Republican Party needs to ensure the relationship between the federal government and the individual is one that maximizes freedom and prosperity."

Rubio is running against Gov. Charlie Crist, the early favorite who won the national party's endorsement last summer. But many conservative leaders have never been fond of Crist - considered to be a moderate who backed President Barack Obama's stimulus measure last year - and recent polls suggest Crist's lead over Rubio has narrowed to single digits.

News of the Ryan endorsement comes a day after Florida Republican Party Chairman Jim Greer, appointed by Crist in 2007, resigned his post after being assailed for months by GOP activists who accused Greer of mismanaging party finances and favoring Crist over Rubio in the primary.

Blumenthal is expected to announce his bid for Senate at a news conference at Connecticut Democratic Party headquarters in Hartford Wednesday afternoon.'

Dodd, a five term Democratic senator, plans to announce his retirement Wednesday, two sources close to the lawmaker told CNN. He plans to announce the decision at a news conference just two and half hours before Blumenthal's scheduled event. Dodd, 65, had been considered one of the most vulnerable Democrats seeking re-election in 2010.

The 63-year-old Blumenthal has been Connecticut's attorney general since 1990 and served in the state legislature from 1984 to 1990.

(CNN) - Rob Simmons, a Republican running for the Senate nomination in Connecticut who has been a fierce critic of Sen. Chris Dodd, said in a statement Dodd's decision to retire does not change his own campaign plans:

"I want to thank Senator Chris Dodd for his long service in Congress. While our disagreements have been profound, Heidi and I wish him and his family all the best. Today's announcement does not change my plan to seek and win the Senate seat from Connecticut.

"Whoever the Democratic nominee is, he or she will have to defend the failed Democratic policies of higher taxes, bigger government, exploding debt, and a misguided approach to national security that treats terrorists as mere criminals rather than the enemy combatants that they are. My entire political career is defined by running in tough races and I expect no less this time around, but I believe voters in Connecticut are seeking real changes in the way government operates and I am the only candidate who has the broad experience and track record to deliver for the state and nation."